As a configuration of using a single image sensor for imaging a pair of captured images having a parallax for displaying a three-dimensional captured image, it has been known to include a right-and-left pair of light receiving elements for each of two-dimensionally aligned microlenses, so that a captured image for the left eye is formed based on pixel signals obtained from the light receiving element for the left eye while a captured image for the right eye is formed based on pixel signals obtained from the light receiving element for the right eye. Examples of such image sensor are described in JP2011-515045A (PTL 1), JP2003-523646A (PTL 2), and JP2011-176715A (PTL 3).